Question

Which expression gives the surface area of a sphere with radius r?

A. r2
B. 4r3
C. 4r2
D. 4r2

Answer 1

Area of sphere is given by
`4\cdot \pi\cdot r^2`

Explanation:

The surface area of sphere is given by:

`\text{Area of sphere}=4\cdot \pi\cdot r^2`

Option C and D are correct but
`\pi` is missing in the options

Option A and B are incorrect.

`\pi=3.14` to solve the area of sphere when radius is given a constant value.

Answer 2

The surface area of a sphere is the area of four great circles . . . 4 π r² .

Apparently, either 'C' or 'D' was supposed to be the correct choice,
but the π got lost in the pantry on the way to the printer.